The present invention relates in general to appliance insulation for dampening vibration, reducing noise and thermal protection; the assembly of such insulation to the appliance and methods of production of the assembled insulation. More specifically the present invention relates to insulation apparata and insulation arrangements for applicances such as dishwashers.
When used, either in, on or around various appliances, insulating pads, blankets and covers when formed from bats or mats of insulation material must be cut to a particular peripheral configuration which conforms to the shape and needs of the appliance to be insulated. On a production basis, this conforming to the shape and needs of the appliance requires the use of special cutting dies or similar techniques to somewhat accurately produce the desired pads or panels of insulation. The use of special cutting dies typically generates scrap material which cannot be used and thus adds to the cost of the finished product. A further problem with bats or mats of fibrous material, such as fiberglass, mineral fiber, ceramic fiber, and the like, is that during handling of the mats, small particulate matter (fibers) is released into the surrounding atmosphere. These small particles can cause irritation to the eyes, nose and throat of those individuals required to handle such material and to persons who are generally exposed to the material. Further health problems can also develop over time.
A further limitation of insulation material which comes off of large bats is that the shape is somewhat limited and frequently the most desirable insulation pad or panel for a particular appliance requires a unique or complex shape which cannot be readily made from the flat stock. For these applications, the insulating pads and panels are typically made using plastic foams or high-density molded fibrous insulation. However, plastic foams and molded fibrous insulation are relatively expensive as compared to the cost of bats or mats of flat insulation material.
A further problem with heretofore known insulation devices using a structure which has a cavity or pocket to be filled with insulation is that the insulation will tend to shift or settle leaving voids within the cavity or pocket. The prior art solution was to use bats or mats of insulation material in a bag-like structure and stitch the insulation to the bag walls. This is a time-consuming process requiring many stitch lines. It also results in adversely affecting the insulation capabilities along the stitch lines and causes holes to be made in the bag walls and insulation. Further, this attempted solution will not work with loose, discrete, divided insulation material.
A further concern with insulating appliances involves the manufacture, packaging, and installation. As should be evident from two examples, a hot water heater and a dishwasher, it will be understood that the ideal insulating technique is to fill tightly any voids or openings with an adequate amount of insulation so as to effect desirable vibration dampening, sound insulation and thermal insulation results. In a hot water heater this space is between the actual tank and the surrounding cabinet or tank wall. With regard to the dishwasher, this space is between the outer wall of the dishwasher enclosure and the inside surface of the kitchen cabinet or counterspace where the dishwasher is installed.
One aspect of the present invention has numerous practical applications for sealing and insulating between spaced-apart surfaces. As indicated in certain appliances such as hot water heaters an dishwashers, it is often desirable to have the insulation completely fill the void or area between spaced-apart surfaces for the vibration, noise and heat-transfer benefits. It is, however, difficult to install insulation within a space which is no larger in transverse dimension than the thickness dimension of the insulation which is to be installed therein.
In these applications, it is desirable to use a foam insulation material. Typically, the foam insulation material is injected in liquid form into the space between the surfaces and allowed to foam up in order to fill the space. It is, however, difficult to seal the space in order to confine the foaming insulation material and prevent the foaming insulation material from leaking out of the space to be insulated. In certain applications such as the under-the-counter dishwasher, the appliance must be removed for servicing and if locked in place within the kitchen cabinetry by foamed insulation, removal will be extremely difficult and reassembly even more so.
One aspect of the present invention involves the use of a thick section or panel of insulation which is enclosed within a pouch or bag to which a vacuum is applied. As the air is drawn out of the insulation, the insulation thickness decreases. The result is a very thick section of insulation reduced down to a substantially thinner section which can then be more easily installed in the space or cavity to be filled. When the vacuum is released and ambient air or even air under pressure is reintroduced into the pouch or bag, the insulation returns to its previous thick section configuration. This expansion back to a normal condition (of thickness) effectively fills the cavity or void and the process may be reversed when the appliance, such as the dishwasher, must be removed for servicing. With regard to the space between the inner tank and the outer shell of the hot water heater, this area for many years has been filled with a flat section of insulation material cut from a mat or bat and rolled around the inner tank. As previously explained, these thicknesses of mat insulation material should be of a thickness or width at least equal to the width of the space between the inner tank and the outer shell in order to provide optimum insulation results. However, this presents a problem when assembling the outer shell concentrically over the inner tank because the mat then physically interferes with the movement of the outer shell over the inner tank. Finally, as previously mentioned, home automatic dishwashing machines are typically installed in a confined space in kitchen cabinetry beneath the countertop. In order to reduce noise transmission generated by the mechanism of the dishwasher machine, it would be advantageous to install acoustical insulation between the dishwasher and cabinetwork. However, the space between the dishwasher machine and cabinetwork is so tight that to date it is virtually impossible to do so.
Since concern over vibration dampening vibration insulation and noise reduction (acoustical insulation) is a significant concern of consumers purchasing automatic dishwasher machines, efforts have been made, notwithstanding the tightness of the space or separation between the dishwasher enclosure and the cabinetwork to provide some form of insulation. This form of insulation typically consists of an outer blanket of flexible insulation such as urethane foam or fiberglass. In addition to acoustical insulation, vibration dampening insulation material may also be applied directly to the dishwasher structure to dampen machine vibrations so that they do not generate airborne noise to and thus become magnified by the cabinetwork and countertop. Since various makes and models of automatic dishwashers have slightly different structural and component location configurations, the specific places where noise absorbing and vibration dampening insulation materials need to be applied will vary. Typically though, some attempt is made to insulate the motor compartment as well as the pumping mechanism against noise and vibration. The outer insulation blanket which is typically used today constitutes the major component of the total dishwasher insulation package. This insulation blanket principally provides acoustical insulation but also functions as a sales feature wherein the size, degree or extent of insulation may be used as a grade or quality designation. It is important for this blanket of insulation to be durable in order to withstand assembly and packaging at the manufacturing plant. Further concerns as to the durability of the insulation blanket involve transportation to the appliance dealer and installation into the kitchen cabinet system at the home of the purchaser.
Most appliance manufacturers package this type of appliance (automatic dishwasher) by placing the appliance in a corrugated container and then sliding tight-fitting corrugated or foam corner posts in each corner of the container and around the corresponding outer edges or corners of the appliance. With the insulation blanket draped around the appliance, this operation of inserting the tight-fitting corner posts can tear or dislodge the insulation blanket whether made from fiberglass or urethane foam.
In addition to concerns over how easily the insulation blanket may tear, either at the time of packaging for shipment to the dealer or when installed beneath the counter within the kitchen cabinetwork, there are health dangers due to handling of such fibrous material as well as irritation due to the airborne particles. It is generally well known that fiberglass and related fibrous materials which are in particulate form or which are machined so as to give off airborne particles are objectionable both to handle and to work with due to irritation of the eyes, nose and throat.
A further concern as previously mentioned is that the manufacturer wants a panel or layer of insulation as thick as possible but he also wants as large a dishwasher tub as possible for increased capacity. These two concerns are obviously not compatible with one another and since the cabinet opening for most automatic dishwashers is of a standard width, a balance must be struck between the dishwasher tub size and the thickness of insulation. The previously mentioned evacuation technique for reducing the thickness of the insulation at the time of installing and then allowing the thickness to resume to a thicker section is particularly valuable to satisfy the manufacturer's desires in this regard.
The present invention which incorporates a number of concepts and structures is particularly well suited to overcome each of the disadvantages and drawbacks with current appliance insulation concepts. The present invention discloses an enclosing structure which enables bat or mat as well as particulate insulation to be enclosed within a more durable pouch or bag so that the problems of insulation tearing during packaging and installation are minimized and handling problems and irritation problems are all but eliminated. A further advantage of the present invention is the ability to incorporate within the enclosed bag or pouch different types and compositions of insulation material such that acoustical absorption as well as vibration dampening may be simultaneously achieved by a single insulation pad applied to the appliance enclosure. This insulation filled bag or pouch is also ideally suited to the pulling of a vacuum as previously mentioned and thus also serves the purpose of creating a very thick section of insulation which can be reduced in thickness for the purposes of installation and then returned to the thicker section for enhanced acoustical absorption and vibration dampening.